Mont. Code § 71-3-303
In case of executions, attachments, and writs of similar nature issued against any person, except for claims for labor done, any miners, mechanics, salespersons, servants, clerks, or laborers who have claims against the defendant for labor done may give notice of their claims and the amount of their claims, sworn to by the person making the claim, to the parties plaintiff and defendant to the action in which the execution, attachment, or other writ has been issued and upon the officer executing the attachment or writ. Service of notice required by this section may be made upon the officer charged with the execution of the writ in one or more cases that may be pending against the person, who shall serve a copy of the notice and claim upon the parties plaintiff and defendant if they are found in the county where the action is pending or upon their respective attorneys employed in the case or cases pending.
§ 71-3-303, MCA